@ori made Nemo_bis an admin on wikitech.wikimedia.org at 2014-09-25T09:29:03 with the comment: "Offered to help with vandal-fighting" (cf. https://wikitech.wikimedia.org/wiki/Special:UserRights/Nemo_bis). Usually, on wikitech.wikimedia.org for that purpose contentadmin is used because admin allows editing the MediaWiki: namespace & Co. and thus has the potential to impersonate users with privileges.
If the intention was to make Nemo_bis a contentadmin, that should be fixed; if admin was indeed intended, that should be reaffirmed with a clear message in the user rights log.